For both styles and scripts, the idea is to output optimized files for browser caching and thus improve users’ experience by reducing loading times. In other words, we use a wide variety of asset sources to assemble a ready-for-prime-time .js and .css files.
There are two main kinds of cards in the asset pipeline: inputters (where the code comes from) and outputters (where it ends up).
Inputters are can be created in multiple ways:
- By adding code to the assets directory in a mod
- By adding remote and/or local assets to a manifest.yml file
- By combining other inputters
- By directly creating cards of an inputter type
adding code to the assets directory
Each mod can have an
assets directory with
By adding CSS or SCSS files to
assets/script) to a mod in use, your code will automatically be included
in standard asset output.
After adding the first asset to a mod, you may need to run
rake card:mod:install (or
the more comprehensive
decko update) for the change to take effect. Otherwise,
everything should pretty much handle itself.
By default, the load order within a mod is alphabetical, and the load order across mods
is governed by the mod load order, which can be seen using
using manifest.yml files
If you want to customize the load order of asset files, you can add a
For example, consider these lines from the manifest.yml file in the bootstrap mod:
libraries is an arbitrary name for the manifest group; you can use any name
remote) as long as it isn’t duplicated in the file. The
the load order for this manifest group.
Note that the manifest also makes it possible to include source files that are not in the assets directory using relative path references.
Manifests also make it possible to include remote files. For example:
- src: https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.6-rc.1/js/select2.full.min.js
combining other inputters
There are various special cards that combine inputters and are inputters themselves:
:style_modscard contains all the standard assets from mods’ asset directories
- Skin cards combine a particular set of styles
(Mod)+:scriptassemble the assets for a given mod
creating inputter cards
Many Cardtypes are coded to be inputters. If you create a card with the type CSS,
for example, it will automatically be treated as an inputter. The same goes for SCSS,
sets include the
Because these cards are intended for Sharks, they are predominantly documented on decko.org
Outputters produce the final asset (.js and .css) files delivered to users’ browsers.
produced on a mod-by-mod basis. The
:all+:script rule maintains a list of all mods
with script inputters, and output is produced for each mod that assembles all the
With style cards, SCSS variables are often shared across many mods, so the output CSS
cannot be constructed on a mod-by-mod basis; it has to be generated across all mods at
once. Thus the site’s main CSS is served as a single file associated with
which typically points to a skin card. The output is managed as a file card at
generating output from input
For each inputter, we generate a VirtualCache card following this pattern:
(Inputter)+:asset_input. This card processes the inputs as much as it safely can.
For example, SCSS cards cannot be converted to CSS here, because they often
involve variables that must be used by other inputters.
When changes to inputters are detected, they trigger changes to all inputters and outputters that depend on them.